R34 RB25 DET Exhaust Manifold Options?

[Ry_R34GTT]

Hey all i recently started pulling down my RB25 DET due to a loss in power and i was planning to send my turbo away to GCG to get it Hi-Flowed anyways.  In the process i found a substantial crack in my exhaust manifold so now i am re thinking the hi flow option as now i need a new exhaust manifold.  My end goal is running 300rwkw which i knew was a stretch for a Hi-Flowed anyway.  My question is now that i need a new manifold am i better off getting an aftermarket manifold and t3/t4 turbo or just replacing it with a stock one and running the Hi-Flowed?

[Griffin]

Stock replacement...

[thebe]

At that power goal and a high-flow Id go stock too. A top mount setup will cost more and be more work. If you want more power in the future (like most of us do after a while ) you can then sell the highflow and go top mount

[Ty1]

Also agree with Stock replacement manifold. Get it ceramic coated too [emoji5][emoji106] they look 100 times better.

[Ry_R34GTT]

Thanks for the reply's.   They do look better ceramic coatedhaha. Does anyone know what the power limit is on the stock manifold? and where i can source a new one?

 

[Piggaz]

Surely there would be a few floating around with guys upgrading.

FWIW, stock manifold, GTX 3071 IWG with supporting mods and boost away.

[thebe]

I sold my normal rb25det manifold for 20€ here in Finland. I assume you can get a good condition used one for similar price elsewhere too as people are going top Mount all the time and just want to get rid of the oem stuff.

 

I wouldnt bother with coating. Save the money for something else

[Griffin]

They are usually on eBay for around $80. I'm making over 400 depending on dyno with one on rb26. 

[Dose Pipe Sutututu]

Watch me make 450kW+ on a stock modified manifold ?

[Ty1]

Apparently you can still get them new from nissan for $300-$500 lol

[KiwiRS4T]

New price at $300 - $500 is OK - my top mount cost $1600 although you can get cheaper ones. Stock one will easily do 300RWKW. I bought a highflowed RB25 turbo from GCG many years ago - today I would definitely go with Hypergear

[Missileman]

stock manifolds crack for two reasons, aftermarket exhausts weigh considerably more than stock, so they need that support bracket near the cat, it often doesn't get replaced. The second issue is the torque wrench is impossible to get into the engine bay to tighten up the manifold nuts, use an open ended spanner on the torque wrench to get a hand feel for the required torque, then replicate that torque as you are tightening the the nuts...also FFS buy a new set of studs, yokes and washers when you change the manifold, as the mani heats up it grows, too tight, or old yokes and washer and the mani will not be able to move as it should.

[Ty1]

I sold my normal rb25det manifold for 20€ here in Finland. I assume you can get a good condition used one for similar price elsewhere too as people are going top Mount all the time and just want to get rid of the oem stuff.
 
I wouldnt bother with coating. Save the money for something else

Ceramic coating is seriously one of the best things you can do for manifolds or any exhaust parts. Increases the lifespan whilst maximizing heat transfer. Not too expensive either. Cost me $200 to get the manifold coated

[thebe]

Ceramic coating is seriously one of the best things you can do for manifolds or any exhaust parts. Increases the lifespan whilst maximizing heat transfer. Not too expensive either. Cost me $200 to get the manifold coated

Sure it might be good for them. However most oem manifolds are still rocking good after 25 years so dont think coating them is gonna do much. And even if it did, you could just buy of new good condition second hand one for less than the coating costs. Id rather use that 200$ on a better spec turbo.